diff --git a/internal/cloud/code-agent-agentrun-adapter.ts b/internal/cloud/code-agent-agentrun-adapter.ts
index dc63aef0..5d6979d8 100644
--- a/internal/cloud/code-agent-agentrun-adapter.ts
+++ b/internal/cloud/code-agent-agentrun-adapter.ts
@@ -435,11 +435,8 @@ export async function syncAgentRunChatResult({ traceId, currentResult = null, op
   const fetchImpl = options.fetchImpl ?? globalThis.fetch;
   const managerUrl = resolveAgentRunManagerUrl(env, mapped.agentRun.managerUrl);
   const timeoutMs = parsePositiveInteger(env.HWLAB_CODE_AGENT_AGENTRUN_HTTP_TIMEOUT_MS, 20_000);
-  const eventsResponse = await agentRunJson(fetchImpl, managerUrl, `/api/v1/runs/${encodeURIComponent(mapped.agentRun.runId)}/events?afterSeq=${encodeURIComponent(String(mapped.agentRun.lastSeq ?? 0))}&limit=500`, {
-    method: "GET",
-    timeoutMs
-  });
-  const events = Array.isArray(eventsResponse?.items) ? eventsResponse.items : [];
+  const eventsResponse = await fetchAgentRunEventsForTrace({ fetchImpl, managerUrl, timeoutMs, mapping: { ...mapped.agentRun, traceSummary: mapped.traceSummary } });
+  const events = eventsResponse.events;
   appendAgentRunEventsToTrace(traceStore, traceId, events, mapped.agentRun);
   const result = await agentRunJson(fetchImpl, managerUrl, `/api/v1/runs/${encodeURIComponent(mapped.agentRun.runId)}/commands/${encodeURIComponent(mapped.agentRun.commandId)}/result`, {
     method: "GET",
@@ -448,7 +445,7 @@ export async function syncAgentRunChatResult({ traceId, currentResult = null, op
   const nextMapping = {
     ...mapped.agentRun,
     ...agentRunResultRefs(result),
-    lastSeq: Math.max(Number(mapped.agentRun.lastSeq ?? 0), Number(result?.lastSeq ?? 0), ...events.map((event) => Number(event?.seq ?? 0))),
+    lastSeq: agentRunTraceCursorSeq(eventsResponse, mapped.agentRun.lastSeq),
     status: result?.status ?? mapped.agentRun.status ?? "running",
     runStatus: result?.runStatus ?? mapped.agentRun.runStatus ?? null,
     commandState: result?.commandState ?? mapped.agentRun.commandState ?? null,
@@ -469,13 +466,10 @@ export async function refreshAgentRunTrace({ traceId, result = null, options = {
   const fetchImpl = options.fetchImpl ?? globalThis.fetch;
   const managerUrl = resolveAgentRunManagerUrl(env, mapped.agentRun.managerUrl);
   const timeoutMs = parsePositiveInteger(env.HWLAB_CODE_AGENT_AGENTRUN_HTTP_TIMEOUT_MS, 20_000);
-  const eventsResponse = await agentRunJson(fetchImpl, managerUrl, `/api/v1/runs/${encodeURIComponent(mapped.agentRun.runId)}/events?afterSeq=${encodeURIComponent(String(mapped.agentRun.lastSeq ?? 0))}&limit=500`, {
-    method: "GET",
-    timeoutMs
-  });
-  const events = Array.isArray(eventsResponse?.items) ? eventsResponse.items : [];
+  const eventsResponse = await fetchAgentRunEventsForTrace({ fetchImpl, managerUrl, timeoutMs, mapping: { ...mapped.agentRun, traceSummary: mapped.traceSummary } });
+  const events = eventsResponse.events;
   appendAgentRunEventsToTrace(traceStore, traceId, events, mapped.agentRun);
-  const lastSeq = Math.max(Number(mapped.agentRun.lastSeq ?? 0), ...events.map((event) => Number(event?.seq ?? 0)));
+  const lastSeq = agentRunTraceCursorSeq(eventsResponse, mapped.agentRun.lastSeq);
   if (lastSeq !== Number(mapped.agentRun.lastSeq ?? 0)) {
     options.codeAgentChatResults?.set?.(traceId, { ...mapped, agentRun: { ...mapped.agentRun, lastSeq, updatedAt: nowIso(options.now) } });
   }
@@ -1293,11 +1287,64 @@ function appendAgentRunEventsToTrace(traceStore, traceId, events, mapping = {})
   }
 }
 
+async function fetchAgentRunEventsForTrace({ fetchImpl, managerUrl, timeoutMs, mapping = {} }) {
+  const runId = requiredString(mapping.runId, "runId");
+  const currentCommandId = typeof mapping.commandId === "string" ? mapping.commandId : "";
+  const { afterSeq, endSeq } = agentRunTraceReplayWindow(mapping);
+  const path = `/api/v1/runs/${encodeURIComponent(runId)}/events?afterSeq=${encodeURIComponent(String(afterSeq))}&limit=500`;
+  const response = await agentRunJson(fetchImpl, managerUrl, path, { method: "GET", timeoutMs });
+  const rawEvents = Array.isArray(response?.items) ? response.items : [];
+  const events = rawEvents.filter((event) => agentRunEventBelongsToTrace(event, { currentCommandId, afterSeq, endSeq }));
+  return {
+    events,
+    afterSeq,
+    endSeq,
+    commandFiltered: Boolean(currentCommandId),
+    maxSeq: Math.max(afterSeq, ...rawEvents.map((event) => Number(event?.seq ?? 0))),
+    traceLastSeq: Math.max(afterSeq, ...events.map((event) => Number(event?.seq ?? 0)).filter(Number.isFinite))
+  };
+}
+
+function agentRunTraceCursorSeq(eventsResponse = {}, previousLastSeq = 0) {
+  const afterSeq = Number(eventsResponse.afterSeq ?? 0);
+  const endSeq = Number(eventsResponse.endSeq ?? 0);
+  const traceLastSeq = Number(eventsResponse.traceLastSeq ?? 0);
+  if (Number.isFinite(traceLastSeq) && traceLastSeq > afterSeq) return Math.floor(traceLastSeq);
+  if (Number.isFinite(endSeq) && endSeq > 0) return Math.floor(endSeq);
+  if (eventsResponse.commandFiltered === true) return Math.max(Number(previousLastSeq ?? 0), afterSeq);
+  return Math.max(Number(previousLastSeq ?? 0), Number(eventsResponse.maxSeq ?? 0));
+}
+
+function agentRunTraceReplayWindow(mapping = {}) {
+  const eventStartSeq = Number(mapping.eventStartSeq ?? mapping.commandStartSeq ?? mapping.startSeq ?? 0);
+  const summary = mapping.traceSummary && typeof mapping.traceSummary === "object" ? mapping.traceSummary : null;
+  const summaryAgentRun = summary?.agentRun && typeof summary.agentRun === "object" ? summary.agentRun : null;
+  const summaryLastSeq = Number(summaryAgentRun?.lastSeq ?? summary?.lastSeq ?? 0);
+  const currentLastSeq = Number(mapping.lastSeq ?? 0);
+  const endSeq = Number.isFinite(summaryLastSeq) && summaryLastSeq > 0 ? Math.floor(summaryLastSeq) : 0;
+  if (Number.isFinite(eventStartSeq) && eventStartSeq > 0) return { afterSeq: Math.max(0, Math.floor(eventStartSeq) - 1), endSeq };
+  if (endSeq > 0) return { afterSeq: Math.max(0, endSeq - 500), endSeq };
+  if (Number.isFinite(currentLastSeq) && currentLastSeq > 0) return { afterSeq: Math.floor(currentLastSeq), endSeq: 0 };
+  return { afterSeq: 0, endSeq: 0 };
+}
+
+function agentRunEventBelongsToTrace(event, { currentCommandId = "", afterSeq = 0, endSeq = 0 } = {}) {
+  const eventCommandId = agentRunEventCommandId(event);
+  const seq = Number(event?.seq ?? 0);
+  if (currentCommandId && eventCommandId && eventCommandId !== currentCommandId) return false;
+  if (endSeq > 0 && Number.isFinite(seq)) return seq > afterSeq && seq <= endSeq;
+  return true;
+}
+
+function agentRunEventCommandId(event) {
+  const payload = event?.payload && typeof event.payload === "object" ? event.payload : {};
+  return typeof payload.commandId === "string" ? payload.commandId : "";
+}
+
 function isForeignAgentRunCommandEvent(event, mapping = {}) {
   const currentCommandId = typeof mapping.commandId === "string" ? mapping.commandId : "";
   if (!currentCommandId) return false;
-  const payload = event?.payload && typeof event.payload === "object" ? event.payload : {};
-  const eventCommandId = typeof payload.commandId === "string" ? payload.commandId : "";
+  const eventCommandId = agentRunEventCommandId(event);
   return Boolean(eventCommandId && eventCommandId !== currentCommandId);
 }
 
diff --git a/internal/cloud/server-agent-chat.test.ts b/internal/cloud/server-agent-chat.test.ts
index b568dbbb..1b754adb 100644
--- a/internal/cloud/server-agent-chat.test.ts
+++ b/internal/cloud/server-agent-chat.test.ts
@@ -1662,6 +1662,102 @@ test("cloud api trace returns persisted summary when live trace store has expire
   }
 });
 
+test("cloud api trace replays an earlier AgentRun command after same-run lastSeq advances (#955)", async () => {
+  const calls = [];
+  const firstTraceId = "trc_issue955_first_trace";
+  const codeAgentChatResults = new Map();
+  const runId = "run_issue955_replay";
+  const firstCommandId = "cmd_issue955_first";
+  const secondCommandId = "cmd_issue955_second";
+  const firstFinalText = "目前只有一个 HWPOD 可用：\n\n- d601-f103-v2 (board: D601-F103-V2 / STM32F103)\n\nAPI 返回 count=1, availableCount=1。";
+  const firstEvents = [
+    { id: "evt_issue955_first_setup", runId, seq: 1, type: "backend_status", payload: { phase: "runner-job-created", commandId: firstCommandId, jobName: "agentrun-v01-runner-issue955-first", namespace: "agentrun-v01" }, createdAt: "2026-06-06T01:43:25.000Z" },
+    { id: "evt_issue955_first_tool", runId, seq: 18, type: "tool_call", payload: { method: "item/completed", type: "commandExecution", toolName: "commandExecution", itemId: "call_issue955_hwpod_list", command: "/bin/sh -lc 'hwpod list --available'", status: "completed", exitCode: 0, outputSummary: '{"count":1,"availableCount":1,"ids":["d601-f103-v2"]}', commandId: firstCommandId }, createdAt: "2026-06-06T01:43:42.000Z" },
+    { id: "evt_issue955_first_assistant", runId, seq: 27, type: "assistant_message", payload: { commandId: firstCommandId, itemId: "msg_item_0", text: firstFinalText }, createdAt: "2026-06-06T01:43:55.000Z" },
+    { id: "evt_issue955_first_terminal", runId, seq: 35, type: "terminal_status", payload: { commandId: firstCommandId, terminalStatus: "completed" }, createdAt: "2026-06-06T01:43:56.000Z" }
+  ];
+  const secondEvents = [
+    { id: "evt_issue955_second_setup", runId, seq: 47, type: "backend_status", payload: { phase: "runner-claim-waiting-for-stale-lease" }, createdAt: "2026-06-06T01:45:56.000Z" },
+    { id: "evt_issue955_second_assistant", runId, seq: 58, type: "assistant_message", payload: { commandId: secondCommandId, itemId: "msg_item_0", text: "编译成功！来总结一下结果。" }, createdAt: "2026-06-06T01:46:24.000Z" },
+    { id: "evt_issue955_second_terminal", runId, seq: 66, type: "terminal_status", payload: { commandId: secondCommandId, terminalStatus: "completed" }, createdAt: "2026-06-06T01:46:28.000Z" }
+  ];
+  const agentRunServer = createHttpServer(async (request, response) => {
+    const url = new URL(request.url || "/", "http://127.0.0.1");
+    calls.push({ method: request.method, path: url.pathname, afterSeq: url.searchParams.get("afterSeq") });
+    if (request.method === "GET" && url.pathname === `/api/v1/runs/${runId}/events`) {
+      response.writeHead(200, { "content-type": "application/json" });
+      response.end(`${JSON.stringify({ ok: true, data: { items: [...firstEvents, ...secondEvents] }, traceId: "trc_fake_issue955_replay" })}\n`);
+      return;
+    }
+    response.writeHead(404, { "content-type": "application/json" });
+    response.end(`${JSON.stringify({ ok: false, message: `unexpected ${request.method} ${url.pathname}` })}\n`);
+  });
+  await new Promise((resolve) => agentRunServer.listen(0, "127.0.0.1", resolve));
+
+  const agentRunPort = agentRunServer.address().port;
+  codeAgentChatResults.set(firstTraceId, {
+    accepted: true,
+    status: "completed",
+    shortConnection: true,
+    traceId: firstTraceId,
+    conversationId: "cnv_issue955_replay",
+    sessionId: "ses_issue955_replay",
+    threadId: "thread-issue955-replay",
+    ownerUserId: TEST_AGENT_ACTOR.id,
+    ownerRole: TEST_AGENT_ACTOR.role,
+    reply: { role: "assistant", content: firstFinalText },
+    finalResponse: { text: firstFinalText, textChars: firstFinalText.length, role: "assistant", status: "completed", traceId: firstTraceId, valuesPrinted: false },
+    traceSummary: { traceId: firstTraceId, source: "agent-session-snapshot", sourceEventCount: 41, terminalStatus: "completed", agentRun: { runId, commandId: firstCommandId, lastSeq: 35, valuesPrinted: false }, valuesPrinted: false },
+    agentRun: { adapter: "agentrun-v01", managerUrl: `http://127.0.0.1:${agentRunPort}`, runId, commandId: firstCommandId, lastSeq: 66, terminalStatus: "completed", valuesPrinted: false },
+    valuesPrinted: false
+  });
+  const traceStore = createCodeAgentTraceStore();
+  const server = createCloudApiServer({
+    traceStore,
+    codeAgentChatResults,
+    env: {
+      HWLAB_CODE_AGENT_ADAPTER: "agentrun-v01",
+      AGENTRUN_MGR_URL: `http://127.0.0.1:${agentRunPort}`,
+      HWLAB_CODE_AGENT_AGENTRUN_ALLOW_NON_K3S_URL: "1",
+      HWLAB_ENVIRONMENT: "v02",
+      HWLAB_GITOPS_PROFILE: "v02"
+    },
+    accessController: {
+      required: false,
+      async authenticate() {
+        return { ok: true, actor: TEST_AGENT_ACTOR, session: TEST_AUTH_SESSION };
+      }
+    }
+  });
+  await new Promise((resolve) => server.listen(0, "127.0.0.1", resolve));
+
+  try {
+    const { port } = server.address();
+    const response = await fetch(`http://127.0.0.1:${port}/v1/agent/chat/trace/${firstTraceId}`, {
+      headers: { cookie: "hwlab_session=test-stub-session" }
+    });
+    assert.equal(response.status, 200);
+    const body = await response.json();
+    const text = JSON.stringify(body);
+    assert.equal(body.traceId, firstTraceId);
+    assert.equal(body.status, "completed");
+    assert.ok(calls.some((call) => call.path === `/api/v1/runs/${runId}/events` && call.afterSeq === "0"));
+    assert.ok(body.events.some((event) => event.commandId === firstCommandId && event.label === "item/commandExecution:completed"));
+    assert.ok(body.events.some((event) => event.commandId === firstCommandId && event.label === "agentrun:assistant:message"));
+    assert.equal(body.events.some((event) => event.commandId === secondCommandId), false);
+    assert.equal(body.finalResponse.text, firstFinalText);
+    assert.match(text, /d601-f103-v2/u);
+    assert.doesNotMatch(text, /编译成功/u);
+  } finally {
+    await new Promise((resolve, reject) => {
+      server.close((error) => (error ? reject(error) : resolve()));
+    });
+    await new Promise((resolve, reject) => {
+      agentRunServer.close((error) => (error ? reject(error) : resolve()));
+    });
+  }
+});
+
 test("cloud api result polling compacts large runnerTrace while preserving providerTrace", async () => {
   const workspace = await mkdtemp(path.join(os.tmpdir(), "hwlab-agent-result-compact-"));
   const codexHome = await mkdtemp(path.join(os.tmpdir(), "hwlab-agent-result-compact-codex-home-"));
diff --git a/internal/cloud/server-code-agent-http.ts b/internal/cloud/server-code-agent-http.ts
index b27c6b31..dc6ffb2e 100644
--- a/internal/cloud/server-code-agent-http.ts
+++ b/internal/cloud/server-code-agent-http.ts
@@ -1835,8 +1835,8 @@ export async function handleCodeAgentTraceHttp(request, response, url, options)
 }
 
 function traceSnapshotWithPersistentFallback(snapshot, persistedResult, traceId, refreshError = null) {
-  if (snapshot?.status !== "missing") return snapshot;
   const fallback = persistentTraceFallback(persistedResult, traceId);
+  if (snapshot?.status !== "missing") return traceSnapshotWithPersistentEvidence(snapshot, fallback, refreshError);
   if (!fallback) return {
     ...snapshot,
     ok: false,
@@ -1878,6 +1878,31 @@ function traceSnapshotWithPersistentFallback(snapshot, persistedResult, traceId,
   };
 }
 
+function traceSnapshotWithPersistentEvidence(snapshot, fallback, refreshError = null) {
+  if (!fallback) return snapshot;
+  return {
+    ...snapshot,
+    conversationId: snapshot.conversationId ?? fallback.conversationId,
+    sessionId: snapshot.sessionId ?? fallback.sessionId,
+    threadId: snapshot.threadId ?? fallback.threadId,
+    agentRun: snapshot.agentRun ?? fallback.agentRun,
+    finalResponse: snapshot.finalResponse ?? fallback.finalResponse,
+    traceSummary: snapshot.traceSummary ?? fallback.traceSummary,
+    fallback: snapshot.fallback ?? (refreshError ? {
+      available: true,
+      source: fallback.source,
+      refresh: {
+        attempted: true,
+        ok: false,
+        code: refreshError?.code ?? "agentrun_trace_refresh_failed",
+        message: refreshError?.message ?? "AgentRun trace refresh failed; live events may be partial.",
+        valuesPrinted: false
+      },
+      valuesPrinted: false
+    } : undefined)
+  };
+}
+
 function persistentTraceFallback(result, traceId) {
   if (!result || typeof result !== "object") return null;
   const storedSummary = result.traceSummary && typeof result.traceSummary === "object" ? result.traceSummary : null;
diff --git a/tools/src/hwlab-cli/trace-renderer.ts b/tools/src/hwlab-cli/trace-renderer.ts
index a65063b5..d76bf99d 100644
--- a/tools/src/hwlab-cli/trace-renderer.ts
+++ b/tools/src/hwlab-cli/trace-renderer.ts
@@ -68,6 +68,10 @@ export function traceDisplayRows(trace: Record<string, unknown> = {}, events: Tr
     rows.push(traceDisplayRow(trace, event));
   }
   if (completionEvent) {
+    const finalResponseText = traceFinalResponseText(trace);
+    if (finalResponseText) {
+      lastAssistantRowIndex = upsertAuthoritativeFinalResponseRow(rows, assistantRows, completionEvent, finalResponseText);
+    }
     const lastAssistantRow = lastAssistantRowIndex >= 0 ? rows[lastAssistantRowIndex] : undefined;
     if (lastAssistantRow) rows[lastAssistantRowIndex] = markAssistantRowTerminal(trace, lastAssistantRow, completionEvent);
     else rows.push(traceCompletionSummaryRow(trace, completionEvent));
@@ -78,6 +82,13 @@ export function traceDisplayRows(trace: Record<string, unknown> = {}, events: Tr
 interface AssistantRowState {
   rowIndex: number;
   comparableText: string;
+  sourceEvent: TraceEvent;
+  derivedSnapshotSuffix?: boolean;
+}
+
+interface AssistantSnapshotDecision {
+  action: "replace" | "append-suffix" | "keep-existing";
+  suffixText?: string;
 }
 
 function traceToolCallRow(trace: Record<string, unknown>, event: TraceEvent): TraceEventRow {
@@ -157,7 +168,7 @@ function upsertAssistantMessageRow(rows: TraceEventRow[], assistantRows: Assista
   const comparableText = comparableAssistantText(row.body);
   if (!comparableText) {
     rows.push(row);
-    assistantRows.push({ rowIndex: rows.length - 1, comparableText });
+    assistantRows.push({ rowIndex: rows.length - 1, comparableText, sourceEvent: event });
     return rows.length - 1;
   }
 
@@ -168,11 +179,31 @@ function upsertAssistantMessageRow(rows: TraceEventRow[], assistantRows: Assista
     if (!existingRow) continue;
     if (state.comparableText === comparableText) {
       rows[state.rowIndex] = mergeAssistantRows(existingRow, row);
+      state.sourceEvent = event;
+      state.derivedSnapshotSuffix = false;
       return state.rowIndex;
     }
     if (comparableText.includes(state.comparableText)) {
+      const previousIndex = comparableText.indexOf(state.comparableText);
+      if (state.derivedSnapshotSuffix === true && previousIndex === 0) {
+        rows[state.rowIndex] = mergeAssistantRows(row, existingRow);
+        state.comparableText = comparableText;
+        state.sourceEvent = event;
+        state.derivedSnapshotSuffix = false;
+        return state.rowIndex;
+      }
+      const snapshotDecision = assistantSnapshotDecision(comparableText, state.comparableText, event, state.sourceEvent);
+      if (snapshotDecision.action === "append-suffix" && snapshotDecision.suffixText) {
+        const suffixRow = { ...row, body: snapshotDecision.suffixText };
+        rows.push(suffixRow);
+        assistantRows.push({ rowIndex: rows.length - 1, comparableText: snapshotDecision.suffixText, sourceEvent: event, derivedSnapshotSuffix: true });
+        return rows.length - 1;
+      }
+      if (snapshotDecision.action === "keep-existing") return state.rowIndex;
       rows[state.rowIndex] = mergeAssistantRows(row, existingRow);
       state.comparableText = comparableText;
+      state.sourceEvent = event;
+      state.derivedSnapshotSuffix = false;
       return state.rowIndex;
     }
     if (state.comparableText.includes(comparableText)) {
@@ -182,10 +213,67 @@ function upsertAssistantMessageRow(rows: TraceEventRow[], assistantRows: Assista
   }
 
   rows.push(row);
-  assistantRows.push({ rowIndex: rows.length - 1, comparableText });
+  assistantRows.push({ rowIndex: rows.length - 1, comparableText, sourceEvent: event });
   return rows.length - 1;
 }
 
+function upsertAuthoritativeFinalResponseRow(rows: TraceEventRow[], assistantRows: AssistantRowState[], completionEvent: TraceEvent, finalText: string): number {
+  const comparableText = comparableAssistantText(finalText);
+  let matchedState: AssistantRowState | null = null;
+  for (const state of assistantRows) {
+    const row = rows[state.rowIndex];
+    if (!row || row.bodyFormat !== "markdown") continue;
+    row.terminal = undefined;
+    if (!matchedState && state.comparableText === comparableText) matchedState = state;
+  }
+  if (matchedState) {
+    const row = rows[matchedState.rowIndex];
+    rows[matchedState.rowIndex] = {
+      ...row,
+      body: finalText,
+      terminal: true,
+      tone: "ok",
+      header: `${traceClock(completionEvent.createdAt)}  助手最终消息`
+    };
+    matchedState.comparableText = comparableText;
+    matchedState.derivedSnapshotSuffix = false;
+    return matchedState.rowIndex;
+  }
+  rows.push({
+    rowId: `trace-final-response:${completionEvent.seq ?? "completed"}`,
+    seq: numberOrNull(completionEvent.seq),
+    tone: "ok",
+    header: `${traceClock(completionEvent.createdAt)}  助手最终消息`,
+    terminal: true,
+    body: finalText,
+    bodyFormat: "markdown"
+  });
+  assistantRows.push({ rowIndex: rows.length - 1, comparableText, sourceEvent: completionEvent });
+  return rows.length - 1;
+}
+
+function assistantSnapshotDecision(nextText: string, previousText: string, nextEvent: TraceEvent, previousEvent: TraceEvent): AssistantSnapshotDecision {
+  if (!sameAssistantSnapshotIdentity(nextEvent, previousEvent)) return { action: "replace" };
+  if (isAuthoritativeAssistantEvent(nextEvent) || isAuthoritativeAssistantEvent(previousEvent)) return { action: "replace" };
+  const previousIndex = nextText.indexOf(previousText);
+  if (previousIndex < 0) return { action: "replace" };
+  const suffixText = nextText.slice(previousIndex + previousText.length).trim();
+  if (suffixText && suffixText.length >= Math.max(80, previousText.length / 3)) return { action: "append-suffix", suffixText };
+  if (previousIndex > 0 || !suffixText) return { action: "keep-existing" };
+  return { action: "replace" };
+}
+
+function sameAssistantSnapshotIdentity(left: TraceEvent, right: TraceEvent): boolean {
+  const leftItem = nonEmptyString(left.itemId ?? left.messageId ?? left.id);
+  const rightItem = nonEmptyString(right.itemId ?? right.messageId ?? right.id);
+  if (leftItem && rightItem) return leftItem === rightItem;
+  return false;
+}
+
+function isAuthoritativeAssistantEvent(event: TraceEvent): boolean {
+  return event.replyAuthority === true || event.final === true || event.terminal === true || String(event.status ?? "") === "completed";
+}
+
 function mergeAssistantRows(preferred: TraceEventRow, metadata: TraceEventRow): TraceEventRow {
   return {
     ...preferred,
@@ -199,6 +287,11 @@ function comparableAssistantText(value: unknown): string {
   return cleanTraceText(value).replace(/\s+/gu, " ");
 }
 
+function traceFinalResponseText(trace: Record<string, unknown>): string | null {
+  const response = trace.finalResponse && typeof trace.finalResponse === "object" ? trace.finalResponse as Record<string, unknown> : null;
+  return nonEmptyString(response?.text ?? response?.content ?? response?.message);
+}
+
 function markAssistantRowTerminal(trace: Record<string, unknown>, row: TraceEventRow, completionEvent: TraceEvent): TraceEventRow {
   return {
     ...row,
diff --git a/web/hwlab-cloud-web/src/state/trace-renderer.test.ts b/web/hwlab-cloud-web/src/state/trace-renderer.test.ts
index 7c433d8f..a188c1b4 100644
--- a/web/hwlab-cloud-web/src/state/trace-renderer.test.ts
+++ b/web/hwlab-cloud-web/src/state/trace-renderer.test.ts
@@ -66,6 +66,31 @@ test("web trace rows do not fold progress assistant text into the final response
   assert.doesNotMatch(terminalRows[0]?.body ?? "", /Let me check|当前工作区还没有/u);
 });
 
+test("web trace rows keep clean AgentRun final response when same itemId snapshots stay running (#955)", () => {
+  const progressOne = "好，我来走 HWPOD 编译路径。先看看 hwpod 命令是否可用，并读取 hwpod-cli 技能了解完整的编译流程。";
+  const progressTwo = "好，现在用 hwpod build 走编译。根据 skill，标准路径是 hwpod build 触发 hwpod-compiler-cli，再通过 API 发给 hwpod-node。";
+  const finalText = "编译成功！来总结一下结果：\n\n hwpod build ✅ completed\n\n- 设备: D601-F103-V2 (STM32F103)\n- 工具链: Keil MDK，通过 keil-cli.py build 异步发起\n- 构建命令: py -3 keil-cli.py build -p atk_f103.uvprojx -t USART\n- exit code: 0，任务已入队列\n- 预期产物: F:\\Work\\D601-HWLAB\\projects\\01_baseline\\Output\\atk_f103.hex\n- 无 blocker";
+  const events: Record<string, unknown>[] = [
+    { seq: 1, label: "agentrun:request:accepted", status: "accepted", createdAt: "2026-06-06T01:46:11.000Z" },
+    { seq: 17, source: "agentrun", sourceSeq: 48, label: "agentrun:assistant:message", type: "assistant", status: "running", itemId: "msg_item_0", message: progressOne, createdAt: "2026-06-06T01:46:15.000Z" },
+    { seq: 22, source: "agentrun", sourceSeq: 53, label: "agentrun:assistant:message", type: "assistant", status: "running", itemId: "msg_item_0", message: progressTwo, createdAt: "2026-06-06T01:46:18.000Z" },
+    { seq: 26, source: "agentrun", sourceSeq: 57, label: "agentrun:assistant:message", type: "assistant", status: "running", itemId: "msg_item_0", message: `${progressOne}${progressTwo}${finalText.slice(0, 170)}`, createdAt: "2026-06-06T01:46:24.000Z" },
+    { seq: 27, source: "agentrun", sourceSeq: 58, label: "agentrun:assistant:message", type: "assistant", status: "running", itemId: "msg_item_0", message: finalText, createdAt: "2026-06-06T01:46:25.000Z" },
+    { seq: 30, source: "agentrun", sourceSeq: 61, label: "agentrun:assistant:message", type: "assistant", status: "running", itemId: "msg_item_0", message: `${progressOne}${progressTwo}${finalText}`, createdAt: "2026-06-06T01:46:26.000Z" },
+    { seq: 36, label: "agentrun:result:completed", type: "result", status: "completed", terminal: true, message: "AgentRun result is ready for HWLAB short-connection polling.", createdAt: "2026-06-06T01:46:28.000Z" }
+  ];
+
+  const rows = traceDisplayRows({ startedAt: "2026-06-06T01:46:11.000Z", finalResponse: { text: finalText } }, events);
+  const assistantRows = rows.filter((row) => row.bodyFormat === "markdown");
+  const terminalRows = assistantRows.filter((row) => row.terminal === true);
+
+  assert.equal(terminalRows.length, 1);
+  assert.equal(terminalRows[0]?.body, finalText);
+  assert.doesNotMatch(terminalRows[0]?.body ?? "", /好，我来走 HWPOD 编译路径|好，现在用 hwpod build/u);
+  assert.equal(assistantRows.filter((row) => /好，我来走 HWPOD 编译路径/u.test(row.body ?? "")).length, 1);
+  assert.equal(assistantRows.filter((row) => /好，现在用 hwpod build/u.test(row.body ?? "")).length, 1);
+});
+
 test("web trace rows collapse tool start/completed and clean shell command escaping", () => {
   const events: Record<string, unknown>[] = [
     { seq: 1, label: "agentrun:request:accepted", status: "accepted", createdAt: "2026-06-04T12:13:58.212Z" },